Table LCommon Operating Difficulties for Oil BurnersConditionCheck forFurnace pulsates on starting, stopping, or during Proper adjustment of the nozzle electrode assembly landoperation.blast tube in relation to each other and firebox.Improper draft. Ensure no downdraft. Leaks in chimney.Defective nozzle.Air in the line, between fuel unit and nozzle.Flame is raw and stingy.Too large an opening in the air adjustment.Partly plugged nozzle.Air in the pump.Ignition points collect carbon.Ignition points too close to nozzle.Nozzle loose in holder.Improper oil cutoff when burner is shutdown.Oil pump is noisy.Air in oil line.Leaks in suction line.Plugged strainer.Burner starts and stops too frequently.Thermostat is improperly wired.Thermostat is improperly adjusted.Drive arm adjustment is incorrect.Limit control is set too low.Plugged air filters.Nozzle is too large for unit.Burner failsafe is activated.Low voltage occurring at night.Incorrect polarity of wiring.Primary control or stack switch improperly adjusted.No oil at the nozzleFuel too low in the supply tank.Plugged nozzle.Leak in the suction line.Leak in the vacuum-gauge port.Pump failing to turn.Leaking strainer gasket.Leaking pump-shaft seal.Fuel unit not operating.AII-20